Dual-Metal Oxide on Cellulose Nanofibers for Advanced Supercapacitors

The effective use of cellulose-based materials in energy applications has attracted significant global attention because of their potential contribution to environmental sustainability. However, the use of eco-friendly materials for energy storage remains challenging because of limitations in cycling stability. In this study, bimetallic oxides such as copper oxide (CuO)–manganese oxide (MnO2) was deposited on cellulose nanofibers (CNFs) through a simple one-step synthesis, and the resulting composite was evaluated for supercapacitor applications. The prepared material, referred to as the cellulose nanofiber/CuO–MnO2 composite (CCM), was characterized using field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). TEM images confirmed the formation of a robust interfacial architecture. The electrochemical performance of the prepared materials was subsequently evaluated for energy storage applications. At a current density of 0.5 mA/cm2, pristine CNF exhibited a specific capacitance of 81.25 F/g, whereas CCM achieved 266 F/g at the same current density and retained 96.1% of its capacitance after 10,000 cycles. These results demonstrate the potential of CCM as an energy-storage material owing to its cycling stability, cost-effectiveness, and environmentally friendly nature, making it a potential alternative to conventional metal oxide-based materials for energy applications.